


Machine Hearts

by The_Local_Cryptid



Category: NieR: Automata (Video Game), 僕のヒーローアカデミア | Boku no Hero Academia | My Hero Academia
Genre: Aizawa is just a mess, Android Midoriya Izuku, Bakugou Katsuki Swears A Lot, Bakugou Katsuki is Bad at Feelings, Bakugou Katsuki is a Good Friend, Engineer Midoriya Izuku, He has to get dating advice from Mic, I just wanted this story out there to please the ravenous appetite of the people, Machine Midoriya Izuku, Midoriya Izuku Has a Quirk, Midoriya Izuku is a Dork, Non-Binary Izuku Midoriya, Romantically speaking, These plot holes are here for ventilation, also technically, for now at least, no beta we die like men, technically, you'll see why - Freeform
Language: English
Status: In-Progress
Published: 2020-12-12
Updated: 2020-12-12
Packaged: 2021-03-10 17:54:39
Rating: Teen And Up Audiences
Warnings: Graphic Depictions Of Violence
Chapters: 1
Words: 4,574
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/28031232
Author URL: https://archiveofourown.org/users/The_Local_Cryptid/pseuds/The_Local_Cryptid
Summary: Izuku’s quirk is odd. Transmutation, but not turning lead to gold, no. He can create machines. And he intends to be a hero with this power.It certainly helps that his best friend and mentor are so supportive.Basically, Izuku can create Machines from NiER: Automata. Supportive friend Bakugou and step-father Aizawa are here to help him along to be a hero
Relationships: Aizawa Shouta | Eraserhead & Midoriya Izuku, Aizawa Shouta | Eraserhead/Midoriya Inko, Bakugou Katsuki & Midoriya Izuku
Comments: 23
Kudos: 90





	Machine Hearts

**Author's Note:**

> Heeeyyyyy guys, uh... Been a while, huh? Not as long as it took the last time I took a break, but damn, I just feel like an old man puttering his way down a live racetrack. That is to say, SLOW. But! I have a bunch of things semi-ready, just need to polish some things up, and fix stuff. This story is not beta read, so bear with me here. I can get it beta read later on down the line but I honestly just wanna throw it out there as soon as possible. Enjoy!

Izuku woke up one day, his four year old body inexplicably drowsy.    
  
He went about his normal morning routine much more sluggish than usual, but he didn’t even have the energy to be mad about it. He eventually shuffled miserably into the kitchen, where at least the smell of Katsudon made him march to a slightly more bearable beat. He saw his mom busying herself, back turned to him as she hummed along to a song he barely heard playing on the radio. Once she heard him sit in his chair, she turned around, her sweet smile dropping nearly instantly.   
  
“Good morning sleepy- IZUKU!?” she suddenly shouted, causing him to jump despite his tired state. “What..?” he said slowly, indicating another thing wrong to the now worried mother. “What happened to you? Is this your quirk!? Oh my God let me call the doctor!’ She frantically said, pulling out her phone quickly. Izuku was worried about what she meant by ‘what happened to you?’ and the prospect of him finally getting his quirk was energizing, so he got out of his chair quickly and padded over to the nearest bathroom, clambering his small body onto the counter with unusual ease.    
  
What he saw shocked him. Instead of his vibrant green hair, it had turned into a snowy white color, and his eyes were as blue as aquamarine. It was… strange to see himself with different colors, he had to admit. He also noted that, despite his already light skin tone, he was visibly paler. He touched his skin, the flesh feeling soft, and his hair felt thick and fluffy as always. So far so good, nothing physically different about him aside from his appearance. 

While his mother explained the situation, he continued to give his body a self-examination. Everything seemed to be in order, from what he remembered, so he settled for waiting until the doctor tells him about his quirk. This had to be part of his quirk, right? He’s never read of people changing, even to this small degree, for no reason.   
  
A short car ride over to a local clinic had them going through a few tests and exams, but he forgot half of the process. His excitement kept building for the time the doctors tell him about how cool and powerful his quirk is. Kacchan can make things go boom! Maybe his quirk can be stronger than All Mights!

They walked into the exam room with a short, round man with a bald head, but more than making up for it with his, honestly ludicrous, facial hair, who introduced himself as Dr. Tsubasa. He gestured for the two to sit. “Hello, hello, I’ll cut straight to the chase. Your son possesses the extra toe joint that is usually found in quirkless people, but there’s obviously been some change, so we did a little digging to see if he was one of the rare cases. See, when there’s a toe join in a human, it adds an extra layer of instability into the mix. Oftentimes these quirks are complete mutations from family lines, and can be quite powerful. Due to this, your son will have to attend quirk therapy for a while, however long depends on the intensity of the quirk and his control over it.”   
  
Inko nodded at his brief but descriptive run-down, making a note to look up quirk therapy later.    
  
Dr. Tsubasa leaned forward onto his knees, turning his bespectacled gaze to the child. “As for you, young man, you’ll be happy to know that your quirk, while it may be hard to control, has a very high chance of being quite the powerful one. Maybe even worthy for heroics, if you want to go that route. The therapy will clear up the decision more, so you should take it seriously.” 

  
Izuku nodded intensely, smiling happily. A powerful quirk that could be perfectly suited for heroics? It was a dream come true. He’d just have to work harder to use it properly, and that just makes it even more worthy in his eyes.

The family of two went home happy, with Inko getting Izuku some ice cream to celebrate.    
  
The next day Izuku had burst into the class filled with excitement. Many of them were shocked at his odd appearance, but when the teacher informed them it was because of his quirk coming in, people were immensely intrigued. When Kacchan had asked what his quirk was, Izuku was more than willing to say that he didn’t know because it was a mutation, but it was gonna be a strong one. Bakugou was annoyed at his lack of a show of power to back it up, but relented when Izuku had said that for general safety he had to not do that. That seemed to get through to Katsuki more than “Public quirk use is bad!”   
  
The next few weeks were spent going to a specialized quirk therapist, an elderly lady who was kind despite her darker, brooding outer appearance. She introduced herself as Ishimoto Aizawa, but insisted on Izuku calling her some variation of Grandma. She had found that being more casual when trying out new quirks was somewhat more effective, as it made the stress level of the kids in her care to be as low as possible.

Her quirk was immensely interesting to Izuku. “Stake-Out,” she had called it. When using her quirk, she was able to glean information about the person being observed, and more things were unveiled the longer she spent watching them. This proved immensely useful in longer-term quirk therapy. When Izuku said that it was perfect for the less intense heroics and police work, or even underground work, when the old lady laughed it off.    
  
“I actually was in the police for a bit, and it seems it runs in the family. My son is actually an underground hero, but I don’t know if he’d be too inclined to meet you, at least not now. He’s never been the best with kids,” she laughed. Izuku’s eyes shone with admiration. 

Over just two weeks, Izuku learned many things about his quirk. Through various sessions of Izuku talking about how he feels in various situations, they realized that he was drawn to mechanics and engineering. They both deduced that it was either part of his quirk or it was simply a very rare case of natural aptitude for a skill at a young age, and Mrs. Aizawa decided that whichever way it swung it would be a good idea to delve into it. Either he walks out of this with newfound information about his quirk, a new skill and hobby, or both.

And so with a few trips to the library, he found himself engrossed in the ways that machines had worked, but was sad to find out that much of technological development outside of support gear and various mentions of an enigmatic “I-Island” and their breakthroughs. 

Deciding to test this further, Mrs. Aizawa (Who he had now decided to call Grandma after she had shown up to one session with a tray of cookies and a delightful smile.) had gathered a small array of technological and material scraps to see if he could create something.    
  
That was when they made the first breakthrough.   
  
When he had assorted the parts, his mind was racing with what he could make with these measly scraps alone, but he would need many tools to do so. Despite that logic, however, he couldn’t keep his mind off a particular object. Some form of small bipedal robot, like a toy almost, with large feet and short legs, and humanoid arms with three digits, and a completely spherical head. The longer he thought about it, the harder it was to think of anything else. 

He hardly noticed the glow building at his palm, nor him raising his arm towards the pile. 

With a glow, the materials shook in place, rising while rings of yellow surrounded them. Mrs. Aizawa watched with quiet interest, not willing to disrupt his concentration unless she absolutely needed to.    
  
The pieces floated together, the multiple rings forming one large one around the mass of raw materials, even all the scrap metal and bad wires Izuku had set aside, creating a clump nearly as large as the child himself. The ring expanded until it became a sphere encompassing all the materials, and with a ring it began to shape into something else.

A golden silhouette, slowly becoming a child-sized robot, the body wide and cylindrical with large feet and short legs, with a large spherical head and thin, robotic limbs that ended in a hand with three fingers, just like he had imagined.

The process took about a minute and a half, but for the two it felt like an hour. The glow faded, and with a metallic  _ clang _ the completed robot fell to the floor, it’s LED light eyes dark and unpowered. Mrs. Aizawa was so fixated on the creation of the robot that she almost didn’t realize the vantablack markings crawling up Izuku’s hand. 

He also seemed like he had just run a mile, sweating immensely, his pale face flushed. Once the robot hit the ground, he nearly did too. But the old lady moved quicker than one might think, and she rushed over and caught the fainting boy. 

Setting him on the couch with an ice pack to cool him down, she phoned Inko who was working her shift at the hospital.

“Ishimoto! Did you find out anything about Izu’s quirk?” Inko greeted, having accepted her into the fold since she was helping her son so readily. 

“Yes and no. Can you come over to the clinic real quick? Something happened. Nothing bad, I assure you, just some overexertion from what I  _ assume, _ ” she looked at the mechanical being that was nearly the size of Izuku, “is a very dramatic quirk reveal.”

“O-oh! I’ll be right over! I’ll see you at the clinic!” Inko said, hanging up after they had exchanged goodbyes. Ishimoto shook her head, chuckling. She then called another number. “Shouta, are you busy? … Yeah Yeah, just come over here, I think you’re gonna enjoy this.”

After hanging up, she looked over at the sleeping white-haired child. “You sure know how to start a show, kiddo..” she muttered as she took a quick nap until Inko and Shouta got there.   
  
  
A faint but still very much so heard knock made its way to Izuku’s ears, and the sound of Grandma shuffling around as she got up from her nap to go answer the door roused him from sleep further.   
  
He became acutely aware of the cold pouch of water on his head when it nearly fell off when he sat up. The ice that he had presumed was in there before was nearly all melted, but it was still relatively cold. Izuku looked over to the door to see a number of odd things.

1: his mother, who if he remembered right should be at work right now. 

2: A large robot that was not there before.

And finally, 3: A scruffy man standing in the corner of the room, who looked like he had no idea what to do or say but was trying to play it off as the strong, silent type. He also had a very long but thin scarf. 

The scruffy man was the first to notice he was awake as his mother and pseudo-grandmother were catching up. The man looked like he was trying to say something to him, but gave up after a few seconds of trying, turning to the other two. 

“He’s up.”

And it was with those two words that Izuku was immediately smothered by his mother. “M-mom…! Can’t… breathe!” he managed to wheeze out, and Inko dialed it down a notch. He sucked in a breath now that he wasn’t being put in an industrial car-crushing hug, and he stopped to look at Ishimoto. 

“So um… W-what happened? And why is there that…” he glanced over at the robot, which looked like the one he had specifically envisioned. “Why is that robot there?”   
  
For the first time, the man spoke directly to Izuku. “To answer both, your quirk. My mo-...  _ Ishimoto _ informed me of what happened and asked me to come help in case your quirk went out of control.”

Izuku was too late to warn the man of his Grandma, wielding a rolled-up newspaper, swatted him across the back of the head. “Shouta! Is that any way to refer to your mother?”   
  
This immediately caused the two raven-haired occupants of the house to get into a small argument, but there was no heat behind each other's words. The man, who Izuku now knows as Shouta, slouched in defeat and, hiding his face behind his scarf, muttered a  _ very _ low “...Sorry Mom…” while Mrs. Aizawa stood with her hands on her hips.

“Well then! Izuku, you’ll be happy to know that, from what I’ve observed so far, you have some kind of quirk that not only deals with stuff more in line with support gear, you have a form of telekinesis and what I can only describe as… Oh, what was the word… Transmutation!”   
  
Izuku, still being only four years old, tilted his head in confusion. Shouta sighed. “Means you can take raw materials and form them into something. Example A: that robot,” he monotonously delivered. Izuku’s eyes lit up. 

“Wow! That’s so powerful! Can I make anything? The possibilities!” he rambled on and on while everyone collectively raised some eyebrows. For a four-year-old child, he was very smart. Aizawa’s lips began to curve into a smirk behind his scarf. 

_ This kid has more potential than most heroes already out there…  _

\---------------------

After that had happened, Izuku had rushed to Katsuki and his group as soon as recess hit. 

“Kacchan! Kacchan! We figured out my quirk!”

Katsuki smiled wolfishly. “Hah! It’s about time, Deku!”

Izuku blushed at being called out, but he continued on anyway. “I have a tele-... tekeni.. Telekinetic- transm...mutation? Yeah! Telekinetic-transmutation hybrid!” he said, proud of himself for remembering the long word.

All three looked confused, and Katsuki looked at Izuku. “... What the hell does that mean…?”

Izuku fumbled before looking for words he knew could describe it. “It uh… I can make robots out of scraps!” He decided on. Katsuki’s eyebrows shot up. “Robots, huh? You tested how strong they are yet?” 

Izuku shook his head. “No, but if you come over to my house we could show you!”

Katsuki grinned. “Deal!”

Underneath that grin, he thought to himself.  _ ‘Making robots... That sounds pretty strong!’ _

The bell rang, and the kids all waited for their parents to come pick them up. Katsuki waited next to Izuku, who was bouncing on his feet. Inko and Mitsuki arrived at nearly the same time, talking to each other, when Izuku ran up to Inko, hugging her leg. “Mom! Can Kacchan come over and see the robot?”

Inko looked at Mitsuki, who just shrugged with a smile. “Sure, why not? Gotta admit, kinda curious myself to see my little nephew’s quirk.”

The two kids cheered. 

The walk was short, as they didn’t live too far away from the school, and they entered Izuku’s house. His mother and him lived in a house that, honestly, was a bit too big for either of them, but they didn’t mind. 

Izuku grabbed Katsuki’s hand, leading him towards the living room where they had propped up the robot. It sat there, still and lifeless, as it’s LED eyes remained dark. “Woah…” Katsuki muttered. 

“We still haven’t figured out how to turn it on, but I’m working on it! I think it just needs some more materials to be complete on the inside. And when that happens, I can show you how my quirk works!”

Katsuki was excited at the prospect of that, and nodded. “Hell yeah! This seems cool as shit!”   
  
Mitsuki slapped him across the head. “Language, Katsuki, we’re guests!” she hissed, turning to Inko. “Honestly, I can’t fathom why he curses so much…” Mitsuki huffed, and Katsuki turned his head, yelling “I LEARNED IT FROM YOU, YOU OLD HAG!”

The ensuing shouting match had both Midoriya's backing away but laughing. Inko prepped some food for the group, and Izuku began exploring the robot and it’s insides, trying to figure out how much of what he needed and trying to think of ways to get it, with Katsuki contributing. Mitsuki snapped a picture before calling Masaru to tell him that there’s an impromptu dinner at the Midoriya household and he should come by too. 

“So, Kacchan, do you know any good places to get this stuff?” Izuku asked, hoping his friend had some kind of answer to give them a direction to start in, at the very least.

Katsuki thought for a second. “Hmm… I heard the old hag talking about one of her favorite beaches being covered in trash? That might have some useful scrap.” 

“Do you know the name of the beach?” Izuku asked as he was shoulder deep in a robotic torso.   
  
“No, but I can find out.” Katsuki grinned.

“Wait how-”   
  
“HEY OLD HAG! WHAT WAS THE NAME OF THE BEACH YOU WERE WHINING ABOUT THE YESTERDAY!?”

Izuku jumped, wincing at the volume. Then, the voice of Mitsuki rang out across the whole house, and quite possibly well beyond that.

“DAGOBAH BEACH YOU BRAT! AND DON’T CALL ME A HAG!”

“Told you.” Katsuki smirked. Izuku just looked downright worried. “Does this happen normally…?”

“Oh yeah, it’s no big deal.”

Izuku wasn’t sure why he expected anything different. But now the two had a mission and a location. Dagobah… He’ll have to ask Grandma Ishi about it. 

\-----------------------

  
  


The next day Izuku told Ishimoto about their plans and she approved. Said that if a few kids could clear a beach and use it to their advantage they’d be getting a head start on hero training. Not to mention they’d be doing the community a favor. And thus began their training to become heroes.

However, it would take a while yet. Two years, to be precise, because as determined as they were, determination wouldn’t cut it too well. They had to stay in school and get good grades, and prepare their bodies for the grueling task ahead. The two remained fast friends though, despite the obvious clashes in personality they might have sometimes. But one cannot have a coin with one side. 

Two years of study. Two years of practice. Two years of dreaming. And two years of knowing a few more people. Shouta Aizawa was the enigmatic son of Ishimoto, and he became as close to a father figure as Izuku had ever had, seeing as his own father died in a villain attack when he was only 1 year old. Shouta would never admit it, but Izuku felt like a son to him. He also planned to oversee their training, because “Someone has to be the responsible one.”

And even Izuku, childishly naïve as he may be, could spot the glances his mother and Shouta threw at each other when they were in the same room. He didn’t understand it, but it was fun to watch them bumble around themselves.

On Izuku’s 6’th birthday, the day when his life was supposed to start skyrocketing, he had managed to finish his robot, but… it still didn’t feel complete. There was a hole in the center of it’s chest, like a heart, but he didn’t know what to make for it.    
  
Izuku was, for lack of a better word, in a slump. But then he had a revelation. If his quirk showed and told him what to make the first time, what’s stopping him from doing it again?

He tried to concentrate on the feeling. Usually he would hold his hand on the machine and then the scrap he would manage to bring home would mend with the robot. Now he was thinking of what, exactly, he needs to make.

He felt his body begin heating up, his heart started pumping faster, he could physically  _ feel _ his brain working, putting together materials and energy requirements, outputs, everything. 

His brain eventually conjured a strange sight. No engine, no battery, nothing. Just a vantablack sphere, if it could be called that. It was more like a small nuclear reactor assembled to look like a sphere. Holding it, it was incredibly dense. The object was the size of perhaps a kickball, and Izuku knew it was hollow inside to store the power, but when he held it it felt like it weighed a hundred pounds. 

He had to use his telekinesis to put it into the slot in the machine’s torso. When he did so, he saw it flash, perhaps recognizing that it was now in a machine that needed powering, and the receptacle closed with a clang. Izuku could almost physically feel the electricity traveling through the wires like they were his own nerves. There was a series of clicks and whirs as the internals tested themselves out, before the eyes lit up with a bright yellow. 

It moved its limbs, turning its spherical head to analyse them with scanners that Izuku subconsciously knew were in its eyes. Once it was finished, it turned to Izuku and, by leaning forward on its legs,  _ bowed  _ politely.    
  
Izuku returned the gesture, but only out of confusion and the spirit of being polite even to a machine.

It spoke, the voice sounding heavily digitized. **“Greetings, Creator.”**

“H-hello…?” he replied, looking it over as the machine, in turn, inspected him.   
  
**“My designation is SS-001, and I am your first creation. Whatever you require of me, I will do.”**

“Uh… alright. Just hang out here for a bit, I need to get my mom.”   
  
**“Affirmative. Standing by for further orders.”**

It took to taking small, waddling steps around the living room, probably scanning everything in sight. Izuku’s six year old feet padded through the hallway and he knocked on his mother’s door. “Mom! The robot’s alive!”   
  
He heard some constant muffled noises stop, along with a small amount of shuffling, and Inko appeared at the door, looking down at him with a sweet smile. She smelled of peaches and had a towel wrapped around her head. “I’m sorry, what’d you need sweetie?”   
  
Izuku pointed down the hall. “I finished my robot!” he cheered, flashing a toothy smile. Inko straightened up. “Oh! Hold on Izuku, let me get my phone, Ishimoto and the Bakugous will want to see.” she said, going into her room once more. 

Satisfied, Izuku went back into the living room, where Ichi (Temporary name until he can come up with one that’s better) was still wandering around. Its large metal feet made a constant series of dull thunks on the hardwood floor. It spotted Izuku. Its eyes flashed green as it raised its arm, the wrist turning left and right. It was waving. 

Izuku waved back. 

**“Greetings, Creator. Did you find this ‘Mom’ individual?”**

“Y-yeah, I did. She’s gonna be here soon, and so a few other people.”

**“Affirmative. Do you have any commands for me?”**

“N-no, not yet?”

It nodded, before it wandered into the kitchen. Izuku watched it go with intense interest, but he held off. He wants to wait for Katsuki to see the machine before asking questions, at least. 

Inko came bustling through, messing with her phone as she dialed in a number.    
  
“Mitsuki? Yeah, the machine’s up and running. Bring Katsuki if you can.”

Izuku, despite being a solid ten feet away and the phone was not on speaker, could clearly hear the barking laugh of his aunt. 

_ “Ha! It’s about damn time that thing’s up! KATSUKI! WE’RE GOING OVER TO INKO’S, THE ROBOT’S RUNNING!” _

Inko held the phone away from her ear with a wince when Mitsuki started shouting. Amazingly, Izuku thought he could almost hear Katsuki’s voice being picked up on the phone. 

\---------------------------

After calling Ishimoto as well to inform her of what had happened, there was a loud pounding on the door that could only belong to one family. Inko rushed over to greet them, and Bakugou immediately rushed in.    
  
“Deku! Where’s the robot!?” he shouted. Izuku, who was watching Ichi look around the kitchen, shouted back. “In here, Kacchan!”

There was a quick series of steps as Katsuki skidded into the room, eyes going wide as he saw the machine walking around the room.    
  
“Damn Deku, that looks fuckin sick when it’s not a motionless heap on the floor!”

“Kacchan! You know mom doesn’t like it when you curse in here!” Izuku scolded his friend.    
  
“Oh shit- wait I mean, fuck- oh, damnit- ARGH!” Katsuki took a deep breath. “Alright, sorry nerd. This is just way too cool. You got your own robot! Have you tested how strong it is?”

Ichi waddled up.  **“According to my diagnostics, my current frame could lift 125 kilograms. However, I do not possess sufficient hydraulic fluid to operate at my maximum capacity. Diagnostics suggest my current lifting capabilities are limited to 45 kilograms. This is not taking into account balance or size.”**

Izuku mouthed ‘wow’ while Katsuki let out a low, long whistle. “Dam- er, dang. That’s impressive. He could probably lift us both up, dude.”

Another set of knocks and some polite exchanging of greetings let Izuku know that the Aizawas had entered the premises. He saw the form of Shouta slinking up behind the counter silently like a black panther. Izuku waved, and Katsuki was surprised, but waved as well.    
  
“Shouta!”   
“Aizawa-sensei! The hell are you sneaking around like a cat for?” Both boys greeted. Aizawa fixed Bakugou with a deadpan look.

“Habit. You tend to pick some up when you are in heroics.”   
  
“Not what I meant but good to know.” Katsuki snarked. Shouta glanced at the robot. “So, Izuku, how’s it feel to have completed your robot?”

Izuku hummed in thought. “I feel… I dunno, more complete? I definitely feel more energized, but that might just be the excitement. But I have this new feeling ever since Ichi powered up…” he said, trying to poke and prod the feeling. Suddenly, he  _ felt _ it. He could feel everything going on in Ichi’s body as if it were his own. He pressed further.    
  
Izuku’s body began to glow gold, and both Shouta and Katsuki watched in silent awe and intrigue, knowing that knocking him out of this could mess him up. Shouta quickly slinked off to get the other adults.    
  
Suddenly, after Izuku lighting up all over like a bonfire, the adults returned just in time to see the human-shaped light bulb  _ split. _ Tendrils of golden, glowing energy raced towards Ichi, who had stood still and silent through all of this, and went into it. The small cracks between pieces were filled with golden light, the eyes went dark, and it went limp. Everyone was stunned silent.

And as quickly as it happened, the eyes lit up again with green light, blinked a few times, and it began to look around. A modulated voice, much different from Ichi’s “normal”, began to speak.   
  
“Woah… This is new. But not like,  _ bad _ new. This is good, I think? Kacchan! Look! I’m Ichi!”   
  
The small robot threw its arms to the sides, looking down at itself to the best of its ability. 

  
Katsuki only had one thing to say about the situation.   
  
**_“What the FUUUUU-”_ **

**Author's Note:**

> Hey, if you like what I do, and wanna see some real cool shit like it, consider joining Syber Space! We've got all kinds of writers and other artists who make their homes there, and we'd love it if you came by! 
> 
> https://discord.gg/DHMMB8HXrT


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